From the Fig 1 to 2, the measurement coefficient can be approximated as a constant, that is to say the soot
concentration measurement result is independence of the soot average diameter. From the Fig 3 to 4, the
measurement coefficient can be approximated as a constant, that is to say the soot concentration measurement
result is independence of the soot diameter distribution.
3. The measurement system
3.1. The optical path of the measurement system
The optical system principle of the measurement system is shown in Fig. 5.